[ataripirate]

I have a G540 - everything was fine, then during a project run, it just flipped out. i stopped it, I have a planet CNC USB controller Mk3/4 hooked to it, no matter if I move it manually or via software the z-axis will go in the right direction at first but then starts going the wrong way and is very sporadic. I have unplugged everything many times. I moved the plug from the y axis into the z axis port, it moved in the right direction, put the z-axis in the y-axis port and it was still doing the same thing. unhooked everything and blew it out, hooked up just the z-axis, now it hardly moves at all, again the plugging in the y axis in the z port, it moves in the right direction fine. the motor moves freely when no power.

any ideas on what I need to do to get back up and running properly?

thanks

[CoAMarcus]

Do you have a FAULT LED on the G540 or is it still green? How fast are you moving the motor when you command it to move on that axis?

What sounds like the problem could be is a blown current sense resistor on the G250X. This would shut down one winding on the motor and would allow it to operate at higher speeds but it would be a crapshoot which direction it goes. You would see erratic behavior at low speed and it may switch direction at different resonance zones. If you take the cover off of the G540, remove the motherboard and look at that G250X you will see two 1206 size SMT resistors between the MOSFETs; those are the current sense resistors. One of them may show signs of physical damage that can help quickly diagnose if this is the case or not.

Either way I'd recommend sending that G250X back here for evaluation if you can't send the whole G540 unit. The G540 can function as a 3-axis drive while your G250X is being repaired.

Please follow this link and complete the form to receive an RMA number:

Product Returns | Step Motor Controls

[ataripirate]

no fault light, at first fast as it gets close to as far as it will go, I slow down or as it starts to reverse



thanks

[ataripirate]

i moved the 4th axis g250x to the z axis and get the same issue, the x and y work properly if i plug them into the z axis port.

[CoAMarcus]

That is sounding like that axis drive has been damaged. You can send just that one G250X in for evaluation as previously mentioned and we can fix your damaged drive while you run the G540 with three axes. I'd recommend checking all of your wiring because the most likely cause of this is a short on a motor winding or a short to the current set resistor.

[ataripirate]

it didnt work when i moved the controller,

[ataripirate]

I have taken the g50x from the 4th axis and moved it to the Z-axis, - same
I have tried x & Y in the z axis - they work properly
I have tired the z into the X & Y - tries to move not properly
I have a new motor - same end result
I have a new wire - same end result

any other ideas? I am not sure what else to try?

thanks

[CoAMarcus]

When you say you tried the Z into the X & Y what do you mean? Do you mean that you moved the Z motor to a different axis on the G540 and the problem follows the motor?

If so it sounds like the motor or cabling is bad. Check the DB9 connector and the solder in there to see if a wire has come loose. If one winding is disconnected in there it could do exactly what you are experiencing.